﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace LModBusRTU
{
    public enum TCRC16Endian
    {
        Big = 1,        // 大头在前，既高位在前
        Little = 2,     // 小头在前，既低位在前
    }

    public interface ICRC_GB19582
    {        
        int CRC16(IntPtr fCRCData, int fDataLen);
    }

    /// <summary>
    /// GB19582中CRC计算方法
    /// 2016-01-25
    /// </summary>
    public class CRC16_GB19582 : ICRC_GB19582
    {
        public int CRC16(IntPtr fCRCData, int fDataLen)
        {
            byte[] fCRCBuf = new byte[fDataLen];
            Marshal.Copy(fCRCBuf, 0, fCRCData, fDataLen);
            return CRC16CB(fCRCBuf);
        }

        static byte[] auchCRCHi = new byte[]{
  0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
  0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
  0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
  0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
  0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
  0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
  0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
  0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
  0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
  0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
  0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
  0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
  0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
  0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
  0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
  0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
  0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
  0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
  0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
  0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
  0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
  0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
  0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
  0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
  0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
  0x43, 0x83, 0x41, 0x81, 0x80, 0x40 };


        static byte[] auchCRCLo = new byte[]{
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
  0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
  0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
  0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
  0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
  0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
  0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
  0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
  0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
  0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
  0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
  0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
  0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
  0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
  0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 };

        /// <summary>
        /// 国标CRC计算器
        /// </summary>
        /// <param name="fCRCData">要计算的数据</param>
        /// <param name="fCRCEndian_Big">计算结果高位在前</param>
        /// <returns></returns>
        public static int CRC16GB(byte[] fCRCData, TCRC16Endian fCRCEndian_Big)
        {
            int fTemp = CRC16CB(fCRCData, fCRCData.Length);
            if (fCRCEndian_Big == TCRC16Endian.Little)
            {
                int fiL, fiH;
                fiL = fTemp & 0xFF;
                fiH = (fTemp >> 8) & 0xFF;
                fTemp = fiL << 8;
                fTemp |= fiH;
            }
            return fTemp;
        }

        public static int CRC16GB(byte[] fCRCData,int fDataLen, TCRC16Endian fCRCEndian_Big)
        {
            int fTemp = CRC16CB(fCRCData, fDataLen);
            if (fCRCEndian_Big == TCRC16Endian.Little)
            {
                int fiL, fiH;
                fiL = fTemp & 0xFF;
                fiH = (fTemp >> 8) & 0xFF;
                fTemp = fiL << 8;
                fTemp |= fiH;
            }
            return fTemp;
        }


        /// <summary>
        /// 查表法计算CRC16
        /// </summary>
        /// <param name="fCRCData"></param>
        /// <param name="fDataLen"></param>
        /// <returns></returns>
        private static int CRC16CB(byte[] fCRCData, int fDataLen)
        {
            byte uchCRCHi = 0xFF;
            byte uchCRCLo = 0xFF;
            int uIndex;
            int fi = 0; ;
            int fiResult = 0;
            if (fDataLen <= fCRCData.Length)
                while ((fDataLen--) > 0)
                {
                    uIndex = uchCRCLo ^ fCRCData[fi];
                    uchCRCLo = (byte)(uchCRCHi ^ auchCRCLo[uIndex]);
                    uchCRCHi = auchCRCHi[uIndex];
                    fiResult = (uchCRCHi << 8 | uchCRCLo);
                    fi++;
                }
            return fiResult;
        }

        private static int CRC16CB(byte[] fCRCData)
        {
            return CRC16CB(fCRCData, fCRCData.Length);
        }
        /// <summary>
        /// 计算法A计算CRC16
        /// </summary>
        /// <param name="fCRCData"></param>
        /// <param name="fDataLen"></param>
        /// <returns></returns>
        private static int CRC16JSA(byte[] fCRCData, int fDataLen)
        {
            int crc = 0xffff;
            if (fDataLen <= fCRCData.Length)
                for (int i = 0; i < fDataLen; i++)
                {
                    crc ^= fCRCData[i];
                    for (int j = 0; j < 8; j++)
                    {
                        bool f = (crc & 1) > 0;
                        crc >>= 1;
                        if (f)
                            crc ^= 0xa001;
                    }
                }
            return (crc);
        }
        private static int CRC16JSA(byte[] fCRCData)
        {
            return CRC16JSA(fCRCData, fCRCData.Length);
        }
        /// <summary>
        /// 计算法B计算CRC16
        /// </summary>
        /// <param name="fCRCData"></param>
        /// <param name="count"></param>
        /// <returns></returns>
        private static int CRC16JSB(byte[] fCRCData, int count)
        {
            byte CRC16Lo;
            byte CRC16Hi;   //CRC寄存器     
            byte CL;
            byte CH;       //多项式码&HA001    
            byte SaveHi; byte SaveLo;
            int Flag;
            CRC16Lo = 0xFF;
            CRC16Hi = 0xFF;
            CL = 0x01;
            CH = 0xA0;
            if (count <= fCRCData.Length)
                for (int i = 0; i < count; i++)
                {
                    CRC16Lo = (byte)(CRC16Lo ^ fCRCData[i]); //每一个数据与CRC寄存器进行异或     
                    for (Flag = 0; Flag <= 7; Flag++)
                    {
                        SaveHi = CRC16Hi;
                        SaveLo = CRC16Lo;
                        CRC16Hi = (byte)(CRC16Hi >> 1);      //高位右移一位 
                        CRC16Lo = (byte)(CRC16Lo >> 1);      //低位右移一位 
                        if ((SaveHi & 0x01) == 0x01) //如果高位字节最后一位为1   
                            CRC16Lo = (byte)(CRC16Lo | 0x80);   //则低位字节右移后前面补1  
                        //否则自动补0             
                        if ((SaveLo & 0x01) == 0x01) //如果LSB为1，则与多项式码进行异或      
                        {
                            CRC16Hi = (byte)(CRC16Hi ^ CH);
                            CRC16Lo = (byte)(CRC16Lo ^ CL);
                        }
                    }
                }
            return (CRC16Hi << 8) | CRC16Lo;
        }

        private static int CRC16JSB(byte[] fCRCData)
        {
            return CRC16JSB(fCRCData, fCRCData.Length);
        }

        private static int fResBuf = 0xFFFF;
        public static int CRC16Append(int fValue)
        {
            byte uchCRCHi = 0xFF;
            byte uchCRCLo = 0xFF;
            int uIndex;
            if (fValue>0xFF)
            {
                uchCRCLo = 0xFF;
                uchCRCHi = 0xFF;
                fResBuf = 0xFFFF;
            }
            else
            {
                uchCRCLo = (byte)(fResBuf & 0xFF);
                uchCRCHi = (byte)((fResBuf >> 8) & 0xFF);
                uIndex = uchCRCLo ^ (fValue & 0xFF);
                uchCRCLo = (byte)(uchCRCHi ^ auchCRCLo[uIndex]);
                uchCRCHi = auchCRCHi[uIndex];
                fResBuf = (uchCRCHi << 8 | uchCRCLo);
            }
            return fResBuf;
        }
    }
}

/*
         //CRC16的计算算法 Delphi语言
         //GBT19582
         function CRC16_JS(buf: PByte; len: Integer): Word;
         var
           i, j: Integer;
           chr: Word;
         begin
           Result := $FFFF;
           for j := 0 to len - 1 do
           begin
             chr := PByte(LongWord(buf) + j)^ and $FF;
             Result := Result xor chr;
             for i := 0 to 8 - 1 do
             begin
               if ((Result and 1) <> 0) then
                 Result := (Result shr 1) xor $A001
               else
                 Result := Result shr 1;
             end;
             Result := Result and $FFFF;
           end;
         end;

        function CRC16JS(DataToCal: TBytes; Datalen: integer): Cardinal;
         var
           i, j: integer;
           chr: Word;
         begin
           Result := $FFFF;
           for j := 0 to Datalen - 1 do
           begin
             chr := DataToCal[j] and $FF;
             Result := Result xor chr;
             for i := 0 to 8 - 1 do
             begin
               if ((Result and 1) <> 0) then
                 Result := (Result shr 1) xor $A001
               else
                 Result := Result shr 1;
             end;
             Result := Result and $FFFF;
           end;
         end;

//CRC16的计算算法 C语言
//GBT19582
static uint CRC16(uchar *puchMsg,uint usDataLen)
{
uint r=0xFFFF;
uint chr=0xFFFF;
uchar i,j;
for(j=0;j<usDataLen;j++)
{
chr=(puchMsg[j])&0xFF;
r=r^chr;
for(i=0;i<8;i++)
{
if ((r&1)!=0)
{r=((r>>1)^0xA001);}
else
{r=(r>>1);}
}
}
return(r);
}
         
        unsigned short CRC16(unsigned char buf[], int n)
        {
           unsigned short crc = 0xffff ;
           for(i = 0; i < n; i++)
           {
              crc ^ = buf[i] ;
              for(b = 0; b < 8; b++)
             {
                bool f = crc & 1 ;
                crc >> = 1 ;
                if(f)
                crc ^ = 0xa001 ;
              }
            }
           return(crc) ;
        }
         
        unsigned short CRC16(puchMsg, usDataLen)
        unsigned char * puchMsg ;                    
        unsigned short usDataLen ;                   
        {
        unsigned char uchCRCHi = 0xFF ;            
        unsigned char uchCRCLo = 0xFF ;            
        unsigned uIndex ;                          
        while (usDataLen--)                        
        {
        uIndex = uchCRCLo ^ * puchMsg++ ;        
        uchCRCLo = uchCRCHi ^ auchCRCLo [uIndex] ;
        uchCRCHi = auchCRCHi [uIndex] ;
        }
        return (uchCRCHi << 8 | uchCRCLo) ;
        }
 
 
        static char auchCRCHi[] = {
        0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
        0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
        0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
        0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
        0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
        0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
        0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
        0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
        0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
        0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
        0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
        0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
        0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
        0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
        0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
        0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
        0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
        0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
        0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
        0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
        0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
        0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
        0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
        0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
        0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
        0x43, 0x83, 0x41, 0x81, 0x80, 0x40 } ;
 
 
        static unsigned char auchCRCLo[] = {
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
        0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
        0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
        0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
        0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 } ;
        */
